There's a breakout of an agressive strain of culminaris that has attacked my 20g sorority I only have one female left and a few other fish and she's in terrible shape its killing everyone one @ a time I'm treating so far with salt and waterchanges and garlic soaked foods but I feel @ this point its time to bring out the big guns wich would work better methyleen blue, marycin, or malchite green?

That bites......the strain that is fast moving- not a lot you can do....I would make sure your water temp is low in the 76F range and increase the oxygenation/aeration with some airstones, if you haven't already get the salt dosage up to 3tsp/gal-depending on what other species of fish/livestock is in the tank you may want to QT and lots of water changes to reduce the bacteria
You want an antibiotic to cover both gram negative and gram positive but with the fast moving strain that eats the flesh it usually won't do much more than the salt...but it doesn't hurt to try.......sorry I can't recommend anything......I don't use OTC antibiotic......good luck......

Poor things, it's too bad that you had to run into such terrible luck. I see what you mean about spotting the beginnings of dropsy. Sadly many fish that reach this stage of infection don't make it. If you still want to go ahead and treat her given the prognosis, I recommend a broad spectrum antibiotic, like API's Triple Sulfa or a combination of Maracyn I and Maracyn II together.

It would be best to treat her in a different container with gentle aeration. Keeping the temperature on the low end of the betta's range (75-76F) is a good idea. It will help slow the progress of the bacteria. I always recommend that anyone using antibiotics read this article so that they have an understanding of how antibiotics work, the risks involved, and how to use them responsibly: http://edis.ifas.ufl.edu/fa084

She didn't make it through the night she fought it hard though...I'm hopeing the other fish will pull through since I began treatment and they haven't shown any sighns yet,,,I'm gunna have to disinfect vthe whole tank when its over with is there anything I can safely disinfect my live plants with?

The bacteria that cause columnaris is always in our tank-you can have an out-break due to poor water quality, sudden high temps, stressed fish to name a few reason-the best method is prevention with regular water changes, stable water temps, QT all new fish/livestock-QT any sick fish, proper diet, keep the nitrate at or below 20ppm...etc....general good husbandry practice

I would start making daily water changes on your tank and keep the water temp stable.....

OFL is right, columnaris is usually present in most tanks, but because it is so common in aquaria, many fish have built up an immunity to it. Only when they are put under stress and their immune systems begin to weaken do they usually fall prey to bacteria. There are strains that will attack healthy fish if given the right conditions, of course.

I use potassium permanganate as a disinfectant--you can find it in powder form at ACE hardware if you have one nearby. The good thing about PP is that you can tell the strength of the solution based on color and it doesn't have the nasty strong smell of chlorine bleach, and if you accidentally get a little on your shirt you get nice pink spots instead of white bleach spots. :3 You should look for plant dip and tank disinfecting instructions online, since I can't really describe the color concentration you want with words, lol. Also make sure you understand the risks involved with handling PP--it is an extremely powerful oxidizer and it will explode if it comes into contact with glycerin. It's not something you want to put anywhere near Anti-Freeze, for instance.